A likely source of uncertainty in extracted carrier densities is multiple band occupancy resulting in non-linear Hall effect. Strong non-linearity of transverse resistance with magnetic field of is commonly observed at high carrier density in ionic liquid-gated SrTiO\(_3\)  and LAO/STO [1]}, [2]}. However, only weak deviation from linearity was observed up to 14 T for device 1 and up to 3 T for device 3.
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